There are devices for inserting elements into the ground which comprise:
an insertion arm which is capable of pressing the elements into the ground in accordance with a predetermined pressing direction, and
a mechanism for positioning the insertion arm relative to the ground which is capable of moving the insertion arm relative to the ground with at least six degrees of freedom, along and about three mutually orthogonal axes (X, Y, Z) of a three-dimensional reference system.
The insertion devices are used in particular for inserting into the ground elements for carrying out works. For example, these devices are used in order to insert sole plates into concrete slabs in order to support the rails of a rail track. In particular, this is used when rail tracks are constructed with no ballast or with no cross-member. For example, insertion devices of this type are described in the patent applications EP 0 803 609 and EP 1 178 153.
The insertion arm must be arranged above the ground with a high degree of precision. To this end, it is known to control the movement of the arm in accordance with geographical measurements (see EP 1 178 153).
These devices are satisfactory. However, it is desirable for the precision of the movement of the arm relative to the ground to be further improved.
The invention is intended to satisfy this wish by providing an insertion device in which the arm can be moved with a higher degree of precision.